Abstract

Augmented Reality (AR) is a form of interaction with computers by augmenting objects of the real world with virtual representations of otherwise invisible information.

For a precise augmentation of the user s view of the real world with virtual objects, an up-todate spatial model of the user s environment is essential. Classic AR applications are limited in their range by the scope and the diverse properties of commonly used sensors for tracking.

To obtain such a spatial model in large-scale Ubiquitous Computing environments, for which Augemented Reality is a natural interface, different tracking technologies have to be combined transparently. The concept of Ubiquitous Tracking leads to such a dynamically configurable sensor network providing positional information. An abstraction of the underlying tracking infrastructure is obtained and a uniform query mechanism for spatial information is offered to AR applications.

The spatial model of the environment can be represented by a graph structure. On basis of this high-level description of available measured spatial relationships, information about geometric relationships can be inferred between arbitrary objects, whilst the actual computation of the positional information is provided by a network of interdependent software components.

The concept of Ubiquitous Tracking is introduced to DWARF, a component-based framework to form highly distributed AR systems.
This thesis deals the aggregation of positional information in a distributed AR system built on DWARF. A new middleware component is introduced to DWARF concerning the distributed representation of spatial information. It provides flexible integration mobile clients participating in the AR system. Positional information requested by applications is aggregated on basis of a distributed represenation of available spatial relationships. The actual computation of this information is invoked by configuration of according software components.

Augmented Reality (AR) is a form of interaction with computers by augmenting objects of the real world with virtual representations of otherwise invisible information. For a precise augmentation of the user s view of the real world with virtual objects, an up-todate spatial model of the user s environment is essential. Classic AR applications are limited in their range by the scope and the diverse properties of commonly used sensors for tracking. To obtain such a spatial model in large-scale Ubiquitous Computing environments, for which Augemented Reality is a natural interface, different tracking technologies have to be combined transparently. The concept of Ubiquitous Tracking leads to such a dynamically configurable sensor network providing positional information. An abstraction of the underlying tracking infrastructure is obtained and a uniform query mechanism for spatial information is offered to AR applications. The spatial model of the environment can be represented by a graph structure. On basis of this high-level description of available measured spatial relationships, information about geometric relationships can be inferred between arbitrary objects, whilst the actual computation of the positional information is provided by a network of interdependent software components. The concept of Ubiquitous Tracking is introduced to DWARF, a component-based framework to form highly distributed AR systems. This thesis deals the aggregation of positional information in a distributed AR system built on DWARF. A new middleware component is introduced to DWARF concerning the distributed representation of spatial information. It provides flexible integration mobile clients participating in the AR system. Positional information requested by applications is aggregated on basis of a distributed represenation of available spatial relationships. The actual computation of this information is invoked by configuration of according software components.